Relay



7 Aug; 6,1938. I M; R. MILLER 2,127,341

' RELAY Filed Nov. 26, 1934 I6 lm, n 1P |3 o-e m gl FIG.6

INVENTOR.

MERTON R. MILLER ATTORNEY.

Patented Aug. 16, 1938 UNITED STATES PATENT OFFICE RELAY Delaware Application November 26, 1934, Serial No. 754,696

4 Claims.

The present invention relates in general to relays, and more in particular to sensitive relays of the polarized type. Broadly speaking, the object of the invention is to produce a highly sensitive polarized relay which is inexpensive, highly eificient, and capable of use over long periods Without adjustment.

The improved relay built in accordance with this invention is adapted to numerous circuit requirements. As examples of its utility there may be cited the patent to Robinson, No. 1,852,980, and my co-pending application, S. N. 724, filed May 9, 1934, both of which show circuits in which it may be used. The Robinson patent discloses the construction of a galvanometer contact device which has been found to be very sensitive and fairly satisfactory. This device, however, has the disadvantage of being quite costly, and further it is not adapted to use in all situations because it requires a special base or mounting and cannot be assembled along with ordinary relays on standard relay racks. These objections and others are overcome in the present invention, and a further object, therefore, may be considered to be the provision of an inexpensive sensitive relay which conforms to standard mounting requirements and which may be used to advantage to replace the galvanometer contact device.

The various features of the improved relay will be described in detail hereinafter, reference being made to the accompanying drawing, in which:

Fig. 1 is a top view of the relay;

Fig. 2 is a side view;

Fig. 3 is an end view;

Figs. 4 and 5 are detailed views of the moving coil;

Fig. 6 is a detailed view of the reed mounting arrangement for the moving coil; while Figs. 7 and 8 show a desirable modification of the construction disclosed in the preceding figures.

The complete relay forming the subject matter of this invention comprises two parts. One of these parts is an ordinary relay of standard construction, having any desired arrangement of contacts. The other part includes a magnet, shown herein as a permanent magnet, for setting up a field, and a coil supported for movement in the field. There is also a stop which in the normal position of the moving coil lies between the armature of the standard relay and its core, thus preventing its effective energization. When the moving coil is displaced by current flow therein, the stop is moved out of its former position, thereby permitting effective energization of the standard relay.

Referring now to Figs. 1, 2, and 3, the reference character I indicates an L-shaped bracket upon which the complete relay is mounted. It will be seen that the vertical portion of the bracket conforms in construction to the usual relay mounting strips on which relays are customarily mounted side by side in horizontal rows. It will be understood, therefore, that the new relay may be mounted in the usual manner along with ordinary relays. A simple bracket of the form shown in the drawing is convenient when the relay is used separately, or when the relay has to be portable, in which case the foot forming the lower portion of the bracket may be secured to a suitable base.

Proceeding to describe the relay itself, attention may first be directed to the construction.

of the portion which includes the moving coil and the field in which it moves. The field is established by magnet 2, seen best in Fig. 1. On one leg of this magnet there is secured a, pole piece 3, having the general configuration shown in Fig. 1. The forwardly extending end of this pole piece is bored out as shown clearly in Fig. 2. There is another pole piece 4, cylindrical in shape, which is secured to the other leg of magnet 2 by means of a bracket 5. 4 extends within the opening in pole piece 3 and its diameter is such that an annular space is left between the two pole pieces in which the moving coil I6 is supported.

The coil I6 is shown in dotted lines in Fig. 1,

The pole piece When the form is being made being impregnated with some substance such as shellac which will bind them together and to the form. After applying another layer of paper or other material as a protective coating to the winding, the two ends of the strip 9, see Fig. 5, are bent around the winding until the ends meet. The pin l0, having a head provided to facilitate this purpose, may now be soldered to the strip 9, the solder serving also tohold the ends of the strip securely together.- The pin ll may be attached to the strip 9 on the opposite side of the coil the same way.

The means for supporting the coil I6 includes a bracket I3, one end of which is held under the head of the screw that holds pole piece bracket 5 to the magnet 2. On the other end of bracket I3 there are secured two metallic reeds I4 and I5, Fig. 6, which are clamped to the bracket between two insulators as shown in Fig. 1. The opposite ends of reeds I4 and I5 are also clamped between two insulators, which serve also to attach the coil I6 to the reeds. To this end the flattened portion I2 of pin I I is made slightly thicker than the reeds I4 and I5, so that when the parts are assembled as shown in Fig. 6, the pin II will be firmly clamped between the insulators along with the reeds I4 and I5. Soldering lugs may be pro vided on both ends of reeds I4 and I5. The lugs at the left, Fig. 6, serve as terminals to which the two ends of coil I6 are secured. The two lugs at the right constitute terminals by means of which the coil is connected to an external circuit. It should be stated that the moving coil and supporting parts that are included in the moving element should be made as light as possible. It will be seen that the arrangement shown aifords a comparatively rigid support for the coil I6 as regards movement in any plane perpendicular to the axis of pole piece 4, while movement parallel to the axis of pole piece 4 is permitted. In fact, the reeds I4 and I5 are light and highly flexible so that very little force is required to move the coil.

In order to limit the movement of the coil, two split rings I1 and I8 are provided. These rings fit tightly on the pole piece 4 and are thus held in place by friction. Ring H can be seen in Fig. 1 and the other ring I8 is shown by dotted lines. Ring I8 is adjusted so that it lies close to coil I6 in normal position and therefore prevents any substantial movement of the coil in its direction. Ring I! however is positioned some distance away from the coil and therefore permits the coil to move some distance before it is arrested by engagement with the ring.

In assembling the parts so far described, the magnet 2 and pole piece 4 are first assembled, and the split ring I1 is put in place. The moving coil assembly may then be placed in position, after which the other split ring I8 can be slipped -on to pole piece 4 outside the coil. After the rings I1 and I8 are adjusted to where they belong, the pole piece 3 can be attached. This pole piece is slotted at I9 to provide a space for oscillation of pin I0, and there is also a corresponding slot on the opposite side for pin I I.

The standard relay which forms part of the complete sensitive relay, includes a coil 22, core 24, and an armature 23, the latter controlling a pair of contact springs 20 and 2I. Since the construction is well known it will not be necessary to explain the details. Suflice it to say that the standard relay is mounted on the bracket I underneath the magnet 2 as and in the position shown in the drawing.

On the face of pole piece 3 there is a pin 25, on which there is pivoted the stop member 26. A ring 21, secured to pin 25 by a set screw, pre vents the stop 26 from being displaced. Stop 26 is made of non-magnetic metal, such as bronze or copper, and is provided with a slot at 28 through which the pin I0 projects. The lower end of the stop lies between the armature 23 and the core 24 of the standard relay. There is sufficient space between the armature and core so that the stop can move freely without binding, and consequently when the coil 22 is energized the armature 23 will be attracted and moved toward the core 24 to a certain extent notwithstanding the stop, but the latter prevents full movement of the armature. The springs 26 and 2| are so adjusted that armature 23 cannot close them so long as stop 26 remains between the armature and the core.

The operation of the relay will now be briefly explained. It will be assumed for convenience that the relay is incorporated in a circuit arrangement such as is shown in Fig. l of my copending application hereinafter referred to. As regards this circuit arrangement it will suffice to say that the function of the relay is to close contacts 2!) and 2! responsive to the closure of circuits through coils I6 and 22 in the event that coil I6 receives current over its circuit in the proper direction and of an operative value. Coil 22 of course is always energized amply suflicient to operate the contacts provided such operation is not prevented by the stop 26. It may be stated that the circuit arrangement referred to includes means for first closing the circuit of coil I6, and then momentarily closing the circuit of coil 22 While the circuit of coil I6 remains closed.

Assuming now that the circuit of coil I6 is closed, three different conditions may be presented. First, the current flow may be zero or so small that the coil I6 cannot move responsive thereto; second, the current may be sufiicient to cause movement of the coil, but its direction is such that the coil tends to move toward stop IB;

and third, the current may be sufficient to move 1 the coil, and in the direction of stop II. It will be clear that if either of the first two conditions obtain, the springs 2|] and EI will not be closed together when the coil 22 is energized, for the stop 26 will prevent full operation of armature 23. Under the third condition, however, the coil will move over against stop IT, and in so doing the pin III will swing the stop 26 on its pivot 25 far enough so that the lower end of the stop will no longer intervene between the armature 23 and core 24. Then when the coil 22 is energized the armature 23 will be fully operated and springs 20 and H will be closed together.

It will be observed that the core 24 is shown as having a copper slug or ring 30 on the armature end, which has the effect of delaying the operation of armature 23 when coil 22 is energized. This slug is not especially required in the circuit arrangement mentioned, wherein the circuits of coils I6 and 22 are closed successively, although it is of some advantage in moderating the impact of the armature on the core or stop. In some circuits, however, it may be necessary or more convenient to close the circuits of coils I6 and 22 simultaneously. Under such conditions, the slug 36 delays the operation of armature 23 long enough so that the coil I6 will have time to position the stop 26. In some circuit arrangements it may be desirable to have the relay operate in such a manner that contacts 20 and 2| will always be closed on the energization of coil 22 provided there is no current or current in the wrong direction in coil I6, while if coil I6 carries current in the other direction the contacts 20 and 2H will not be closed responsive to the energization of coil 22. The adjustments necessary to secure the foregoing type of operation will now be described.

Referring to Fig. 7, the split rings I1 and I8 are moved on pole piece 4 to the positions shown in the drawing. This provides for movement of the coil I6 toward ring [8 instead of toward ring l1. Also, referring to Figs. 1 and 2, the screws 3| and 32 which serve to attach the heel piece 34 to the bracket l are removed and the whole permanent magnet assembly is shifted to the right (as observed in Fig. 3). The screws 3i and 32 are then inserted in another set of tapped holes in heel piece 34, one of these holes being indicated by dotted lines at 33, Fig. 1. The result of the foregoing change is to displace the permanent magnet assembly far enough to the right so that the stop 26 will normally stand in the position indicated in Fig. 8, where it cannot interfere with the full operation of armature 23. With the modified arrangement, then, it will be seen that so long as coil I6 is not moved, or moved against ring H, the springs 20 and 2| will be closed every time coil 22 is energized, but if coil I6 is moved over against ring I8, the stop 26 will be swung over between the armature 23 and core 24 so that the armature 23 cannot be operated to close springs 20 and 2|.

In that form of the relay which is shown in the principal figures of the drawing, and also in the modification shown in Figs. '7 and 8, there are two circuits which have to be taken care of, the weak current circuit including coil l6 and the local circuit including coil 22. The systems so far referred to as illustrations of where the relay can be used to advantage are of the type in which the closing of the local circuit of coil 22 at the proper time can readily be taken care of. There are other systems in which this cannot be done, as the sole control must be exercised over the weak current circuit. The sensitive relay shown herein may be used in such systems, provided some delay in response may be tolerated. Assume for example that it is desired to use the sensitive relay to operate a signal or some other piece of apparatus responsive to the establishment of current flow in a photo-cell circuit, and assume further that it is satisfactory if the signal or other device be operated within five seconds of the time the current flow is first set up. The sensitive re lay shown herein may be adapted to these requirements by connecting coil IS in the photocell circuit, so that the coil and stop will be moved whenever current flow begins. To take care of the energization of coil 22 a continuously operating commutator or interrupter is used, the same being adjusted so as to momentarily close the circuit of coil 22 at five second intervals. This arrangement will ensure the closure of contacts 20 and 2| by coil 22 within a five second period following the movement of coil I6, and these contacts can obviously be used to complete a local circuit for a signal or any other device as required.

The invention having been described, that which is believed to be new and for which the protection of Letters Patent is desired will be pointed out in the appended claims.

What is claimed is:

1. As an article of manufacture, a magnetic structure adapted to be assembled along with standard telephone type relays and mounting in the same space as is provided on a mounting plate for such relays, said structure comprising a U- shaped permanent magnet With pole pieces forming an annular air gap, a coil supported for move ment in said gap, a member pivotally suspended from said structure and adapted when the said structure is mounted in a relay mounting space above a telephone type relay to have its lower end interposed between the core and armature of such relay, and a mechanical connection between the said coil and said member to move the latter on its pivot responsive to movement of the coil.

2. In combination, a relay having an armature normally separated from the relay core by an air gap, a magnetic device positioned directly above said relay, a member having one end pivoted on a part of said device so that it hangs freely suspended in the plane of said air gap, the pivot point being so located that in one of the positions which the said member assumes in swinging on its pivot its lower end is interposed between the armature and core of said relay, and means for swinging said member on its pivot responsive to energization of said device.

3. In combination, a relay and an armature therefor, said armature controlled responsive to the energization of said relay to close an electrical circuit, a permanent magnet adjacent said relay, a member normally positioned with one end thereof preventing said armature from closing the circuit when said relay is energized, the other end thereof pivoted on said magnet, a coil winding moveably supported on said magnet, and a pin engaging said pivoted member controlled by the movement of said coil to move said member in an are about said pivot to enable said armature to be controlled by the energization of said relay to close the circuit.

4. In combination, an electro-magnet, an armature for said magnet, a permanent magnet mounted above said electro-magnet, a movable coil winding supported in the magnetic field of said permanent magnet, a pivoted member supported on said permanent magnet having its lower end interposed between said electro-magnet and its armature to prevent the operation of said armature when said electro-magnet is energized,

and means actuated by the movement of said coil for moving the lower end of said member sufficiently to enable said armature to operate when said electro-magnet is energized.

MERTON R. MILLER. 

